Method and Apparatus for Determining Reference Signal Sequence, Computer Program Product, and Computer Readable Storage Medium

ABSTRACT

A method includes receiving, by a terminal device, first indication information sent by a network device. The terminal device determines a target resource based on the first indication information and a reference signal sequence based on parameters of a first bandwidth and parameters of a second bandwidth. The terminal sends or receives the reference signal sequence on the target resource.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/CN2018/085607, filed on May 4, 2018, which claims priority toChinese Patent Application No. 201710313804.0, filed on May 5, 2017. Thedisclosures of the aforementioned applications are hereby incorporatedby reference in their entireties.

TECHNICAL FIELD

This application relates to the communications field and, in specificembodiments, to a method and an apparatus for determining a referencesignal sequence, a computer program product, and a computer readablestorage medium.

BACKGROUND

In a Long Term Evolution-Advanced (LTE-A) system, a supported maximumsystem bandwidth is 20 MHz, and corresponds to a maximum of 110 resourceblocks (RB). For downlink demodulation reference signals (DMRS),reference signal sequences are generated based on a quantity of RBs ofthe maximum bandwidth, and a DMRS on a corresponding RB uses acorresponding reference signal sequence.

Due to insufficient capabilities of some terminal devices (for example,a relatively poor function of a radio frequency device) or anotherreason, these terminal devices cannot transmit data by using a maximumbandwidth, and may be capable of access only a frequency band of arelatively small bandwidth, and this bandwidth may be referred to as acomponent carrier (CC). In LTE-A, a CC may be considered as a servingcell, and a terminal device needs to learn only a cell bandwidth, thatis, a system bandwidth of the CC. Reference signals of the terminaldevice on the CC are generated based on a quantity of RBs correspondingto a maximum bandwidth of LTE-A, and physical resource blocks (PRB) arenumbered starting from a frequency domain start position of the CC. Inthe LTE-A system, the terminal device may transmit data on a pluralityof CCs by using carrier aggregation (CA). In this way, a bandwidth thatmay be used by the terminal device to transmit data is larger, and adata transmission rate is improved.

A new-generation wireless communications system researched and developedfor a 5th generation mobile communications technology (5-Generation, 5G)is referred to as new radio (NR). NR supports a larger bandwidth andmore services. Because terminal devices have different capabilities, NRallows the terminal devices having the different capabilities to use CCsof different bandwidths. Some new concepts such as a bandwidth part (BP)are also proposed in NR.

Resources in NR are allocated more flexibly, and a plurality ofcorporations consider that more flexible multi-user multiple-inputmultiple-output (multi-user Multiple-input multiple-output, MU-MIMO)needs to be considered, for example, MU-MEMO performed when bandwidthsaccessed by a plurality of terminal devices partially overlap with eachother, and MU-MTMO performed by terminal devices on a CC and a widebandCC. In NR, if MU-MIMO between a terminal device operating on a wideband(or wideband CC) and a terminal device operating on a CC or usingaggregation of a plurality of CCs or a terminal device operating on a BPneeds to be supported, DMRSs of the two terminal devices need to beconfigured to be orthogonal or quasi-orthogonal. However, in aconventional method for generating and mapping a DMRS sequence on awideband and a CC in LTE-A, DMRSs of a user operating on a wideband anda user operating on one or more CCs cannot be configured to beorthogonal.

SUMMARY

This application provides a method for determining a reference signalsequence, a terminal device, and a network device, to determine areference signal sequence based on parameters of a first bandwidth andparameters of a second bandwidth, so that a reference signal sequence onthe first bandwidth and a reference signal sequence on the secondbandwidth are the same, and the reference signal sequence on the firstbandwidth and the reference signal sequence on the second bandwidth maybe configured to be the same, orthogonal, or quasi-orthogonal, tosupport MU-MIMO between terminal devices operating on the firstbandwidth and the second bandwidth.

According to a first aspect, a method for determining a reference signalsequence is provided. The method includes: receiving first indicationinformation sent by a network device; determining a bandwidth part basedon the first indication information; determining a reference signalsequence based on an offset between a frequency domain start position ofthe bandwidth part and a frequency domain start position of a maximumsystem bandwidth; and sending or receiving the reference signal sequenceby using the bandwidth part.

In a possible implementation of the first aspect, the method furtherincludes: receiving second indication information sent by the networkdevice; and determining the frequency domain start position of themaximum system bandwidth based on the second indication information.

In a possible implementation of the first aspect, the method furtherincludes: receiving third indication information sent by the networkdevice; and determining the frequency domain start position of thebandwidth part based on the third indication information.

In a possible implementation of the first aspect, the determining areference signal sequence based on an offset between a frequency domainstart position of the bandwidth part and a frequency domain startposition of a maximum system bandwidth includes: determining thereference signal sequence based on a subcarrier spacing and the offsetbetween the frequency domain start position of the bandwidth part andthe frequency domain start position of the maximum system bandwidth.

According to a second aspect, a method for determining a referencesignal sequence is provided. The method includes: sending firstindication information to a terminal device, where the first indicationinformation is used to indicate a bandwidth part; and sending secondindication information to the terminal device, where the seconddictation information is used to indicate a frequency domain startposition of a maximum system bandwidth.

In a possible implementation of the second aspect, the method furtherincludes: sending third indication information to the terminal device,where the third indication information is used to indicate a frequencydomain start position of the bandwidth part.

In a possible implementation of the second aspect, an offset between thefrequency domain start position of the bandwidth part and the frequencydomain start position of the maximum system bandwidth is used by theterminal device to determine a reference signal sequence, and thereference signal sequence is sent by using the bandwidth part.

According to a third aspect, an apparatus for determining a referencesignal sequence is provided, and the apparatus may be a terminal device,or may be a chip in a terminal device. The apparatus may include aprocessing unit and a transceiver unit. When the apparatus is a terminaldevice, the processing unit may be a processor, and the transceiver unitmay be a transceiver; the terminal device may further include a storageunit, and the storage unit may be a memory; and the storage unit isconfigured to store an instruction, and the processing unit executes theinstruction stored in the storage unit, so that the terminal deviceperforms the method for determining a reference signal sequence based onthe first aspect and the implementations of the first aspect. When theapparatus is a chip in a terminal device, the processing unit may be aprocessor, and the transceiver unit may be an input/output interface, apin, a circuit, or the like; and the processing unit executes theinstruction stored in the storage unit, so that the terminal deviceperforms the method for determining a reference signal sequence based onthe first aspect and the implementations of the first aspect. Thestorage unit maybe a storage unit (for example, a register or a cache)in the chip, or may be a storage unit (for example, a read-only memoryor a random access memory) that is in the terminal device and that islocated outside the chip.

According to a fourth aspect, an apparatus for determining a referencesignal sequence is provided, and the apparatus may be a network device,or may be a chip in a network device. The apparatus may include aprocessing unit and a transceiver unit. When the apparatus is a networkdevice, the processing unit may be a processor, and the transceiver unitmay be a transceiver; the network device may further include a storageunit, and the storage unit may be a memory; and the storage unit isconfigured to store an instruction, and the processing unit executes theinstruction stored in the storage unit, so that the network deviceperforms the method for determining a reference signal sequence based onthe second aspect and the implementations of the second aspect. When theapparatus is a chip in a network device, the processing unit may be aprocessor, and the transceiver unit may be an input/output interface, apin, a circuit, or the like; and the processing unit executes theinstruction stored in the storage unit, so that the network deviceperforms the method for determining a reference signal sequence based onthe second aspect and the implementations of the second aspect. Thestorage unit may be a storage unit (for example, a register or a cache)in the chip, or may be a storage unit (for example, a read-only memoryor a random access memory) that is in the network device and that islocated outside the chip.

According to a fifth aspect, an apparatus for obtaining a resourceindication value is provided. The apparatus includes a processor and astorage medium, the storage medium stores an instruction, and when theinstruction is run by the processor, the processor is caused to performthe method for determining a reference signal sequence based on thefirst aspect and the implementations of the first aspect. The apparatusmay be a chip or a chip system.

According to a sixth aspect, an apparatus for obtaining a resourceindication value is provided. The apparatus includes a processor and astorage medium, the storage medium stores an instruction, and when theinstruction is run by the processor, the processor is caused to performthe method for determining a reference signal sequence based on thesecond aspect and the implementations of the second aspect. Theapparatus may be a chip or a chip system.

According to a seventh aspect, a computer program product is provided.The computer program product includes computer program code, and whenthe computer program code is run by a communications device, thecommunications device is caused to perform the method for determining areference signal sequence based on the first aspect and theimplementations of the first aspect.

According to an eighth aspect, a computer program product is provided.The computer program product includes computer program code, and whenthe computer program code is run by a communications device, thecommunications device is caused to perform the method for determining areference signal sequence based on the second aspect and theimplementations of the second aspect.

According to a ninth aspect, a computer readable storage medium isprovided. The computer readable storage medium is configured to store acomputer program, and the computer program includes an instructionconfigured to perform the method for determining a reference signalsequence based on the first aspect and the implementations of the firstaspect.

According to a tenth aspect, a computer readable storage medium isprovided. The computer readable storage medium is configured to store acomputer program, and the computer program is configured to execute aninstruction of the method for determining a reference signal sequencebased on the second aspect and the implementations of the second aspect.

According to an eleventh aspect, a method for determining a referencesignal sequence is provided. The method includes: receiving, by aterminal device, first indication information sent by a network device;determining, by the terminal device, a target resource based on thefirst indication information; determining, by the terminal device, areference signal sequence based on parameters of a first bandwidth andparameters of a second bandwidth; and sending or receiving, by theterminal device, the reference signal sequence on the target resource.

Based on the method for determining a reference signal sequence providedin the eleventh aspect, the reference signal sequence can be determinedbased on the parameters of the first bandwidth and the parameters of thesecond bandwidth, so that a reference signal sequence on the firstbandwidth and a reference signal sequence on the second bandwidth arethe same, and the reference signal sequence on the first bandwidth andthe reference signal sequence on the second bandwidth may be configuredto be the same, orthogonal, or quasi-orthogonal, to support MU-MIMObetween terminal devices operating on the first bandwidth and the secondbandwidth.

In a possible implementation of the eleventh aspect, the parameters ofthe second bandwidth include at least one of the following parameters: acenter frequency of the second bandwidth, a bandwidth value of thesecond bandwidth, and a frequency domain start position of the secondbandwidth.

In a possible implementation of the eleventh aspect, the parameters ofthe first bandwidth include at least one of the following parameters: acenter frequency of the first bandwidth, a bandwidth value of the firstbandwidth, and a frequency domain start position of the first bandwidth.

In a possible implementation of the eleventh aspect, the method furtherincludes: receiving, by the terminal device, second indicationinformation sent by the network device; and determining, by the terminaldevice, at least one of the parameters of the second bandwidth based onthe second indication information.

In a possible implementation of the eleventh aspect, the method furtherincludes: receiving, by the terminal device, third indicationinformation sent by the network device; and determining, by the terminaldevice, at least one of the parameters of the first bandwidth based onthe third indication information.

In a possible implementation of the eleventh aspect, the determining, bythe terminal device, a reference signal sequence based on parameters ofa first bandwidth and parameters of a second bandwidth includes:determining, by the terminal device, the reference signal sequence basedon a subcarrier spacing and the parameters of the first bandwidth, theparameters of the second bandwidth.

In a possible implementation of the eleventh aspect, a frequency domainof the target resource and a frequency domain of the first bandwidth arethe same or partially overlap.

In a possible implementation of the eleventh aspect, the bandwidth valueof the first bandwidth is less than or equal to the bandwidth value ofthe second bandwidth.

In a possible implementation of the eleventh aspect, the first bandwidthis any one of an operating bandwidth of the terminal device, a servingcell bandwidth, and a carrier bandwidth; and the second bandwidth is anyone of a maximum system bandwidth, a cell bandwidth, and a widebandcarrier bandwidth.

According to a twelfth aspect, a method for determining a referencesignal sequence is provided. The method includes: sending, by a networkdevice, first indication information to a terminal device, where thefirst indication information is used to indicate a target resource; andsending, by the network device, second indication information to theterminal device, where the second indication information is used toindicate at least one of parameters of a second bandwidth.

Based on the method for determining a reference signal sequence providedin the twelfth aspect, the network device sends, to the terminal device,the indication information used to indicate the parameters of the secondbandwidth, and MU-MIMO between UE operating on a first bandwidth and theterminal device operating on the second bandwidth may be supported, thatis, a reference signal sequence is determined based on parameters of thefirst bandwidth and the parameters of the second bandwidth. Finally, areference signal sequence on the first bandwidth and a reference signalsequence on the second bandwidth are configured to be the same,orthogonal, or quasi-orthogonal, to support MU-MIMO between the terminaldevices operating on the first bandwidth and the second bandwidth.

In a possible implementation of the twelfth aspect, the method furtherincludes: sending, by the network device, third indication informationto the terminal device, where the third indication information is usedto indicate the parameters of the first bandwidth.

In a possible implementation of the twelfth aspect, the parameters ofthe second bandwidth and the parameters of the first bandwidth are usedby the terminal device to determine a reference signal sequence, and thereference signal sequence is sent on the target resource.

In a possible implementation of the twelfth aspect, the parameters ofthe second bandwidth include at least one of the following parameters: acenter frequency of the second bandwidth, a bandwidth value of thesecond bandwidth, and a frequency domain start position of the secondbandwidth.

In a possible implementation of the twelfth aspect, the parameters ofthe first bandwidth include at least one of the following parameters: acenter frequency of the first bandwidth, a bandwidth value of the firstbandwidth, and a frequency domain start position of the first bandwidth.

In a possible implementation of the twelfth aspect, the bandwidth valueof the first bandwidth is less than or equal to the bandwidth value ofthe second bandwidth.

In a possible implementation of the twelfth aspect, a frequency domainof the target resource and a frequency domain of the first bandwidth arethe same or partially overlap.

In a possible implementation of the twelfth aspect, the first bandwidthis any one of an operating bandwidth of the terminal device, a servingcell bandwidth, and a carrier bandwidth; and the second bandwidth is anyone of a maximum system bandwidth, a cell bandwidth, and a widebandcarrier bandwidth.

According to a thirteenth aspect, a terminal device is provided. Theterminal device includes a processor, a memory, and a transceiver thatare configured to enable the terminal device to perform a correspondingfunction in the foregoing method. The processor, the memory, and thetransceiver are connected by using communication, the memory stores aninstruction, the transceiver is configured to perform specific signalreceiving/transmission under driving of the processor, and the processoris configured to invoke the instruction to implement the method fordetermining a reference signal sequence according to the first aspectand the implementations of the first aspect.

According to a fourteenth aspect, a terminal device is provided. Theterminal device includes a processing module, a storage module, and atransceiver module that are configured to enable the terminal device toperform a function of the terminal device in the first aspect or anypossible implementation of the first aspect. The function may beimplemented by using hardware, or may be implemented by executingcorresponding software by hardware, and the hardware or softwareincludes one or more modules corresponding to the foregoing function.

According to a fifteenth aspect, a network device is provided. Thenetwork device includes a processor, a memory, and a transceiver thatare configured to enable the network device to perform a correspondingfunction in the foregoing method. The processor, the memory, and thetransceiver are connected by using communication, the memory stores aninstruction, the transceiver is configured to perform specific signalreceiving/transmission under driving of the processor, and the processoris configured to invoke the instruction to implement the method fordetermining a reference signal sequence according to the second aspectand the implementations of the second aspect.

According to a sixteenth aspect, a network device is provided. Thenetwork device includes a processing module, a storage module, and atransceiver module that are configured to enable the network device toperform a function of the network device in the second aspect or anypossible implementation of the second aspect. The function may beimplemented by using hardware, or may be implemented by executingcorresponding software by hardware, and the hardware or softwareincludes one or more modules corresponding to the foregoing function.

According to a seventeenth aspect, a communications system is provided.The communications system includes the terminal device according to thethird aspect and the network device according to the fourth aspect. Thecommunications system may complete the methods for determining areference signal sequence according to the first aspect and the secondaspect.

According to an eighteenth aspect, a computer readable storage medium isprovided. The computer readable storage medium is configured to store acomputer program, and the computer program includes an instructionconfigured to perform the method according to the first aspect or anypossible implementation of the first aspect.

According to a nineteenth aspect, a computer readable storage medium isprovided. The computer readable storage medium is configured to store acomputer program, and the computer program includes an instructionconfigured to perform the method according to the second aspect or anypossible implementation of the second aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of sequences of corresponding referencesignals when UE accesses a CC and accesses a maximum bandwidth in theprior art;

FIG. 2 is a schematic diagram of a typical application scenarioaccording to an embodiment of this application;

FIG. 3 is a schematic flowchart of a method for determining a referencesignal sequence according to an embodiment of this application;

FIG. 4 is a schematic diagram of reference signal sequences of differentbandwidths according to an embodiment of this application;

FIG. 5 is a schematic diagram of determining an offset value accordingto an embodiment of this application;

FIG. 6 is a schematic diagram of determining an offset value accordingto another embodiment of this application;

FIG. 7 is a schematic flowchart of a method for determining a referencesignal sequence according to another embodiment of this application;

FIG. 8 is a schematic block diagram of a terminal device according to anembodiment of this application;

FIG. 9 is a schematic block diagram of a terminal device according toanother embodiment of this application;

FIG. 10 is a schematic block diagram of a network device according to anembodiment of this application; and

FIG. 11 is a schematic block diagram of a network device according toanother embodiment of this application.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The following describes technical solutions of this application withreference to accompanying drawings.

In an LTE-A system, a supported maximum system bandwidth is 20 MHz, andcorresponds to a maximum of no RBs. For downlink DMRSs, reference signalsequences are generated based on a quantity of RBs of the maximumbandwidth, a DMRS on a corresponding RB uses a corresponding referencesignal sequence, and a formula for generating a DMRS sequence is shownin Formula (1):

$\begin{matrix}{{{r(m)} = {{\frac{1}{\sqrt{2}}\left( {1 - {2 \cdot {c\left( {2m} \right)}}} \right)} + {j\frac{1}{\sqrt{2}}\left( {1 - {2 \cdot {c\left( {{2m} + 1} \right)}}} \right)}}},{{{where}\mspace{14mu} m} = \left\{ \begin{matrix}{0,1,{{2\mspace{14mu} \ldots \mspace{14mu} 12N_{RB}^{\max,{DL}}} - 1}} \\{0,1,{{2\mspace{14mu} \ldots \mspace{14mu} 16N_{RB}^{\max,{DL}}} - 1}}\end{matrix} \right.}} & (1) \\{c_{init} = {{\left( {\left\lfloor {n_{s}/2} \right\rfloor + 1} \right) \cdot \left( {{2n_{ID}^{n_{SCID}}} + 1} \right) \cdot 2^{16}} + n_{SCID}}} & (2)\end{matrix}$

where c (m) is a pseudo-random sequence (Pseudo-random sequence, PNsequence), and a reference signal sequence r (m) is formed by the PNsequence. c_(init), is an initialization value, and Formula (2) is aformula for generating the initialization value c_(init). N_(RB)^(max,DL) indicates 110 RBs of the downlink maximum bandwidth.

A mapping formula of an LTE downlink DMRS port (port) and atime-frequency resource is shown in Formula (3):

a _(k,l) ^((p)) =w _(p)(l′)·r(3·l′·N _(RB) ^(max,DL)+3·n _(PRB) +m′)  (3)

In Formula 3), p is an antenna port corresponding to a DMRS, k is afrequency domain subcarrier position of the DMRS mapped to thetime-frequency resource, l is a time domain symbol position of the DMRSmapped to the time-frequency resource, n_(PRB) is a physical resourceblock (physical resource block, PRB) number, and W_(p)(l′) is anorthogonal cover code (orthogonal cover code, OCC) corresponding to aport number being p. By using the mapping formula (3), REs of differenttime-frequency resources (a frequency domain number is k and a timedomain symbol number is L) are in a one-to-one correspondence withsequence values r (m). Based on the sequence generation formula and themapping formula, DMRS sequence values on different RBs may be uniquelydetermined.

In downlink MU-MIMO of LTE-A, a plurality of terminal devices mayperform MU-MIMO on a same bandwidth. To be capable of demodulating dataof different users, a base station configures quasi-orthogonal ororthogonal DMRSs for a plurality of UEs. A quasi-orthogonal method isused to configure orthogonal ports for a plurality of users, to achieveorthogonality:by using different OCCs. A method for configuring DMRSports and layers (layer) in LTE-A is provided in Tablet By configuring acorresponding configuration item for a user, a network side device cansupport correct demodulation of DMRSs when a plurality of users performMU-MINO.

TABLE 1 Configuration table of reference signal One code word Two codewords code word 0 is available code word 0 is available code word 1 isunavailable code word 1 is available Configuration Configuration valueInformation value Information 0 one layer, port 7, n_(SCID) = 0 0 twolayers, ports 7 and 8, n_(SCID) = 0 1 one layer, port 7, n_(SCID) = 1 1two layers, ports 7 and 8, n_(SCID) = 1 2 one layer, port 8, n_(SCID) =0 2 three layers, ports 7 to 9 3 one layer, port 8, n_(SCID) = 1 3 fourlayers, ports 7 to 10 4 two layers, ports 7 and 8 4 five layers, ports 7to 11 5 three layers, ports 7 to 9 5 six layers, ports 7 to 12 6 fourlayers, ports 7 to 10 6 seven layers, ports 7 to 13 7 reserved 7 eightlayers, ports 7 to 14

FIG. 1 is a schematic diagram of sequences of corresponding referencesignals when a terminal device accesses different CCs in the prior art.As shown in FIG. 1, numbers 0, 1, 2, . . . , and m in the figure are RBnumbers. At a same position of an entire frequency domain, correspondingreference signal sequences (RB numbers) are different when the terminaldevice accesses different CCs.

If NR needs to support MU-MIMO between terminal devices on a CC and awideband CC or a BP, in a conventional method for generating and mappinga DMRS sequence on CCs in LTE-A, reference signals of the terminaldevices on the CC and the wideband CC or BP on a same frequency bandcannot be configured to be orthogonal.

Based on a problem existing in the foregoing reference signal designmethod in the prior art, this application provides a method fordetermining a reference signal sequence, to better meet a requirement ofsupporting MU-MIMO between a terminal device operating on a wideband (orwideband CC) and a terminal device operating on a CC or usingaggregation of a plurality of CCs, or a terminal device operating on aBP in NR, so that a base station may better demodulate data of differentterminal devices.

It should be understood that, the technical solutions of thisapplication may be applied to various communications systems such as anLTE/LTE-A system, an LTE/LTE-A frequency division duplex (FDD) system,an LTE/LTE-A time division duplex (TDD) system, a Universal MobileTelecommunications System (UMTS), a Worldwide Interoperability forMicrowave Access (WiMAX) communications system, a public land mobilenetwork (PLMN) system, a device to device (D2D) network system ormachine to machine (M2M) network system, a Wireless Fidelity (Wi-Fi)system, a wireless local area network (WLAN), and a future 5Gcommunications system.

It should be further understood that, in this embodiment of thisapplication, a terminal device may also be referred to as user equipment(UE), a mobile station (MS), a mobile terminal, or the like, theterminal device may communicate with one or more core network devices byusing a radio access network (RAN). For example, the terminal device mayinclude various handheld devices, in-vehicle devices, wearable devices,or computing devices having a wireless communication function, oranother processing device connected to a wireless modern. The terminaldevice may further include a user unit, a cellular phone, a smartphone,a wireless data card, a personal digital assistant (PDA) computer, atablet computer, a wireless modem, a handheld device (handset), a laptopcomputer, a machine type communication (MTC) terminal, or a station (ST)in a wireless local area network (WLAN). The terminal device may be acellular phone, a cordless telephone, a Session Initiation Protocol(SIP) telephone, a wireless local loop (WLL) station and anext-generation communications system, for example, a terminal device ina 5th generation communications (fifth-generation, 5G) network or aterminal device in a future evolved public land mobile network (PLMN)network. This embodiment of this application is not limited herein.

It should be further understood that, a base station may also bereferred to as a network device, the network device may be a deviceconfigured to communicate with the terminal device, and the networkdevice may be an evolved NodeB (eNB or eNodeB) in an LTE system, a gNBor an access point in NR, a base transceiver station, a transceivernode, an in-vehicle device, a wearable device, a network device in afuture 5G network, or a network device in a future evolved PLAIN system.For example, the network device may be an access point (AP) in a WLAN,or may be a base station (BTS) in Global System for MobileCommunications (GSM) or Code Division Multiple Access (CDMA). Thenetwork device may further be an evolved NodeB (eNB or eNodeB) in an LTEsystem. Alternatively, the network device may further be a node B (NodeB) in a 3rd Generation (3G) system. Additionally, the network device mayfurther be a relay station, an access point, an in-vehicle device, awearable device, a network device in a future 5G network, a networkdevice in a future evolved PLMN network, or the like. This embodiment ofthis application is not limited herein. For convenience of description,in all the embodiments of this application, the foregoing apparatusesproviding a wireless communication function to an MS are collectivelyreferred to as network devices.

FIG. 2 is a schematic diagram of a typical application scenarioaccording to an embodiment of this application. As shown in FIG. 2, thetechnical solutions of this application may be applied to sending andreceiving of a sequence of a reference signal during uplink and downlinkdata transmission between a network device and a terminal device, thereference signal may be a DMRS, a channel state information-referencesignal (CSI-RS), a sounding reference signal (SRS), a phase trackingreference signal (PTRS), a cell-specific reference signal, a positionreference signal, or the like, and this embodiment of this applicationis not limited herein.

It should be understood that, this embodiment of this application isdescribed by using only the application scenario shown in FIG. 2 as anexample, but this embodiment of this application is not limited thereto.For example, the system may include more terminal devices.

A method for determining a reference signal sequence provided in thisapplication is described in detail below with reference to FIG. 3, FIG.3 is a schematic flowchart of a method 100 for determining a referencesignal sequence according to an implementation of this application, themethod 100 may be applied to the scenario shown in FIG. 2, and certainlymay also be applied to another communication scenario, and thisembodiment of this application is not limited herein.

As shown in FIG. 3, the method 100 includes the following steps.

S110. A terminal device receives first indication information sent by anetwork device.

S120. The terminal device determines a target resource based on thefirst indication information.

S130. The terminal device determines a reference signal sequence basedon parameters of a first bandwidth and parameters of a second bandwidth.

S140. The terminal device sends or receives the reference signalsequence on the target resource.

Specifically, in Silo and S120, when the terminal device needs to senddata on a time-frequency resource, the terminal device also needs tosend a reference signal sequence on this resource. The reference signalsequence is used by the network device to perform channel estimation,coherent detection, and demodulation, so that the network devicecorrectly demodulates data of the terminal device. Therefore, theterminal device receives the first indication information sent by thenetwork device, and the first indication information is used to indicatea time-frequency resource on which the terminal device sends thereference signal sequence, that is, the target resource. The terminaldevice may determine the target resource based on the first indicationinformation.

In S130, after the target resource is determined, the terminal devicedetermines the reference signal sequence based on the parameters of thefirst bandwidth and the parameters of the second bandwidth, so that areference signal sequence on the first bandwidth and a reference signalsequence on the second bandwidth are the same. In this way, when aplurality of terminal devices perform MU-MIMO, for example, MU-MIMObetween a terminal device operating on the first bandwidth and aterminal device operating on the second bandwidth needs to be supported,because the reference signal sequence on the first bandwidth and thereference signal sequence on the second bandwidth are the same, thereference signal sequence on the first bandwidth and the referencesignal sequence on the second bandwidth may be configured to beorthogonal or quasi-orthogonal, and therefore the network device maycorrectly parse out data of different terminal devices. Therefore, thereference signal sequence on the first bandwidth is related to theparameters of the first bandwidth and the parameters of the secondbandwidth, that is, the reference signal sequence on the first bandwidthis determined based on the parameters of the first bandwidth and theparameters of the second bandwidth.

FIG. 4 is a schematic diagram of reference signal sequences of differentbandwidths according to an embodiment of this application. As shown inFIG. 4, a maximum bandwidth may be considered as a second bandwidth, andCC1, a wideband CC2, or a BP may be considered as a first bandwidth; ora wideband CC2, a cell bandwidth, or a maximum bandwidth may beconsidered as a second bandwidth, and CC1 may be considered as a firstbandwidth. Numbers of CC1, the wideband CC2, and the maximum bandwidthare numbers of RBs. Because reference signal sequences of CC1 and thewideband CC2 are generated based on a method for generating a referencesignal sequence of the maximum bandwidth, it may be learned from FIG. 4that, for a fixed frequency domain range, reference signal sequences onthe maximum bandwidth, CC1, and the wideband CC2 may be configured to bethe same, orthogonal, or quasi-orthogonal (numbers of RBs are the same).

When a terminal device a accesses CC1 and a terminal device 2 accessesthe maximum bandwidth, the reference signal sequence on CC1 and thereference signal sequence on the maximum bandwidth may be configured, byusing the configuration in Table 1, to be orthogonal orquasi-orthogonal. In this way, when the terminal device accesses CC1 andthe terminal device 2 accesses the maximum bandwidth, a network devicemay correctly demodulate data of different users.

It should be understood that, in an LTE/LTE-A system, that is, if aplurality of terminal devices do not perform MU-MIMO, the method fordetermining a reference signal sequence provided in this embodiment ofthis application may also be applicable, and this embodiment of thisapplication is not limited herein.

In S140, after determining the reference signal sequence, the terminaldevice sends or receives the reference signal sequence on the targetresource, where the reference signal sequence is used to demodulate dataof different users.

It should be understood that, the target resource is a resourceallocated by the network device to the terminal device, and the terminaldevice may send or receive data on the target resource. A frequencydomain of the target resource and a frequency domain of the firstbandwidth may be the same or partially overlap. The frequency domain ofthe target resource may further be a part of a frequency domain of thesecond bandwidth, or a part of the frequency domain of the firstbandwidth. This embodiment of this application is not limited herein.

Optionally, in an embodiment, the first bandwidth may include any one ofan operating bandwidth of the terminal device, a cell bandwidth servingthe terminal device, and a carrier bandwidth. For example, the firstbandwidth may be a CC, a plurality of CCs after carrier aggregation, aBP, a cell bandwidth, a maximum system bandwidth, or the like. Thesecond bandwidth may include any one of a maxim system bandwidth, a cellbandwidth, and a wideband carrier bandwidth. The frequency domain of thefirst bandwidth may be a part of the frequency domain of the secondbandwidth, or the frequency domain of the first bandwidth and a part ofthe frequency domain of the second bandwidth overlap, and a bandwidthvalue of the first bandwidth may be less than or equal to a bandwidthvalue of the second bandwidth. This embodiment of this application isnot limited herein.

For example, the first bandwidth may be a CC, the CC may be a servingcell bandwidth, a continuous frequency domain resource in a celltransmission bandwidth, a discontinuous frequency domain resource in acell transmission bandwidth, or the like, and this embodiment of thisapplication is not limited herein.

For example, the first bandwidth may be a bandwidth part (BP), the BP isa continuous resource in frequency domain, and one BP may include Kcontinuous subcarriers, where K is an integer greater than 0; one BP mayinclude frequency domain resources on which N non-overlapping continuousPRBs is located, where N is an integer greater than 0, and a subcarrierspacing of the PRB is 15 k, 30 k, 60 k, or another subcarrier spacing;or one BP includes frequency domain resources on which N non-overlappingcontinuous PRB groups is located, and one PRB group includes Mcontinuous PRBs, where N and M are integer's greater than 0, and asubcarrier spacing of the PRB is 15 k, 30 k, 60 k, or another subcarrierspacing. For one terminal device, a length of a BP may be less than orequal to a maximum bandwidth supported by the terminal device, and thisembodiment of this application is not limited herein,

It should be understood that, the first bandwidth may further be abandwidth formed by aggregating CCs based on CA, and this embodiment ofthis application is not limited herein,

It should be further understood that, the first bandwidth may furtherinclude another type of bandwidth, the second bandwidth may also includeanother type of band width, and this embodiment of this application isnot limited herein.

Based on the method for determining a reference signal sequence providedin this embodiment of this application, the reference signal sequencecan be determined based on the parameters of the first bandwidth and theparameters of the second bandwidth, so that a reference signal sequenceon the first bandwidth and a reference signal sequence on the secondbandwidth are the same. When different terminal devices respectivelyaccess the first bandwidth and the second bandwidth to perform MU-MIMO,the reference signal sequence on the first bandwidth and the referencesignal sequence on the second bandwidth may be configured to beorthogonal or quasi-orthogonal. In this way, data of the differentterminal devices may be correctly demodulated, improving userexperience.

Optionally, in an embodiment, the parameters of the second bandwidthinclude at least one of the following parameters: a center frequency ofthe second bandwidth, a bandwidth value of the second bandwidth, and afrequency domain start position of the second bandwidth.

Optionally, in an embodiment, the parameters of the first bandwidthinclude at least one of the following parameters: a center frequency ofthe first bandwidth, a bandwidth value of the first bandwidth, and afrequency domain start position of the first bandwidth.

Specifically, the terminal device obtains the parameters of the firstbandwidth accessed by the terminal device, and the parameters may be,for example, the center frequency of the first bandwidth and thebandwidth value of the first bandwidth. Likewise, after the terminaldevice also obtains the parameters of the second bandwidth, a method forgenerating a reference signal on the first bandwidth may be the same asor different from a method for generating a reference signal on thesecond bandwidth, or a length of the reference signal sequence generatedon the first bandwidth and the second bandwidth needs to be generatedbased on a maximum value of the two bandwidths or another largerbandwidth value. Reference signal sequences of an overlapping part ofthe first bandwidth and the second bandwidth in frequency domain may beconfigured to be the same, orthogonal, or quasi-orthogonal. Because thefrequency domain start position of the first bandwidth and the frequencydomain start position of the second bandwidth may be different, it maybe considered that the frequency domain start position of the firstbandwidth has an offset value relative to the frequency domain startposition of the second bandwidth, and corresponding to a mapping formulaof a reference signal sequence, a mapping formula of the referencesignal sequence on the first bandwidth has an offset value relative to amapping formula of the reference signal sequence on the secondbandwidth. The offset value is related to the parameters of the firstbandwidth and the parameters of the second bandwidth.

An NR standard has agreed that for a subcarrier spacing, a maximumquantity of subcarriers of each NR carrier is 3300 or 6600. Therefore,lengths of reference signal sequences on all wideband CCs or CCs (orBPs) on one carrier are generated based on a maximum bandwidth or amaximum quantity of subcarriers. Using a method for generating a DMRSsequence in LTE as an example, Formula (4) is used in each method forgenerating a sequence of a reference signal on different CCs andwideband CCs or a full bandwidth:

$\begin{matrix}{{{r(m)} = {{\frac{1}{\sqrt{2}}\left( {1 - {2 \cdot {c\left( {2m} \right)}}} \right)} + {j\frac{1}{\sqrt{2}}\left( {1 - {2 \cdot {c\left( {{2m} + 1} \right)}}} \right)}}},{{{where}\mspace{14mu} m} = 0},1,{2\mspace{14mu} \ldots \mspace{14mu} {A \cdot N_{RB}^{\max,{DL}}}}} & (4)\end{matrix}$

In Formula (4), N_(RR) ^(max,DL) indicates a maximum bandwidth value,and because DMRS design of NR may be different from that of LTL, a frontconstant value is replaced with A. Because bandwidths and maximumbandwidths (or maximum quantities of subcarriers) of different cells maybe different, and a bandwidth that may be used by a cell may be lessthan a maximum bandwidth, N_(RB) ^(max,DL) in the formula may furtherindicate a bandwidth of a cell, a wideband bandwidth, a bandwidth afteraggregation of a plurality of CCs, a wideband BP bandwidth, or the like.That is, a generated length of a reference signal sequence on a CC or aBP may be generated based on a bandwidth such as a maximum bandwidth, acell bandwidth, or a wideband. It should be understood that, Formula (4)is described by using only the method for generating a DMRS sequence inLTE as an example. In this embodiment of this application, a method forgenerating a corresponding reference signal sequence NR may be furtherdetermined by using another method for generating a reference signalsequence, and this embodiment of this application is not limited herein.

For a mapping formula of a reference signal, description is performed byusing a DMRS as an example, and it is mentioned above that, a mappingformula of a DMRS port and a time-frequency resource is Formula (3):

a _(k,l) ^((p)) =w _(p)(l′)·r(3·l′·N _(RB) ^(max,DL)+3·n _(PRB) +m′)  (3)

It needs to be ensured that the reference signal sequences of theoverlapping part of the first bandwidth and the second bandwidth infrequency domain may be configured to be the same, orthogonal, orquasi-orthogonal. A DMRS needs to have an offset value (offset) in themapping formula on the first bandwidth, and the offset value is shown inFormula (5) or Formula (6):

a _(k,l) ^((p)) =w _(p)(l′)·r(3·j′·N _(RB) ^(max,DL)+3·n _(PRB)+m′+offset1)   (5)

a _(k,l) ^((p)) =w _(p)(l′)·r(3·l′·N _(RB) ^(max,DL)+3·(n_(PRB)+offset2)+m′)   (6)

A relationship between offset1 in Formula (5) and offset2 in Formula (6)is offset1=3 offset2. The relationship between offset1 and offset2 isrelated to design of a specific DMRS format, and because an actual DMRSformat affects a time-frequency resource position to which a DMRSsequence is mapped, a corresponding used mapping formula is different.

Formula (5) or Formula (6) is a mapping formula of a DMRS on the firstbandwidth, and if Formula (5) or Formula (6) is determined, thereference signal sequence on the first bandwidth is determined. In thisway, when different terminal devices respectively access the firstbandwidth and the second bandwidth to perform MU-MIMO, the referencesignal sequence on the first bandwidth is mapped by using Formula (5) orFormula (6), so that the reference signal sequence on the firstbandwidth and the reference signal sequence on the second bandwidth arethe same. In this way, by using configuration of the network device, thereference signal sequence on the first bandwidth and the referencesignal sequence on the second bandwidth may be configured to beorthogonal or quasi-orthogonal, and the network device may correctlyparse out data sent by each terminal device.

It should be understood that, Formula (5) and Formula (6) use only theDMRS mapping formula of LTE as an example, and in this embodiment ofthis application, adding an offset value to the mapping formula of thefirst bandwidth is also applicable to another DMRS format and acorresponding mapping formula.

Therefore, as long as an offset value of a frequency domain startposition of the first bandwidth relative to that of the second bandwidthcan be determined, the reference signal sequence on the first bandwidthmay be made the same as the reference signal sequence on the secondbandwidth by using respective mapping formulas, and therefore thereference signal sequence on the first bandwidth and the referencesignal sequence on the second bandwidth may be configured to beorthogonal or quasi-orthogonal.

For example, the terminal device may determine a frequency domain startposition f1 of the first bandwidth based on the center frequency of thefirst bandwidth and the bandwidth value of the first bandwidth, and maydetermine a frequency domain start position f of the second bandwidthbased on the center frequency of the second bandwidth and the bandwidthvalue of the second bandwidth. Therefore, a frequency domain offsetvalue of the first bandwidth relative to the second bandwidth is f-f1.The terminal device determines, based on a parameter configuration(numerology) used on the second bandwidth at a current moment or asubcarrier spacing, a frequency domain length of an RB under thesubcarrier spacing, may work out an RB quantity N corresponding to f-f1,and may determine that an offset value is N. As shown in FIG. 5, FIG. 5is a schematic diagram of determining an offset value according to anembodiment of this application. In FIG. 5, a bandwidth (BW) may beconsidered as a second bandwidth, and CC1 or CC2 is independentlyconsidered as a first bandwidth; or CC1 and CC2 may be considered as awideband CC formed by using carrier aggregation, and the wideband CC maybe considered as a first bandwidth. Numbers of CC1, CC2, and the BW areRB numbers. For example, an offset value offsets of CC1 relative to theBW may be determined based on a frequency domain start position and abandwidth value of CC1, and a frequency domain start position and abandwidth value of the BW. Likewise, an offset value offset2 of CC2relative to the BW may also be determined.

Optionally, in an embodiment, in S130, the determining, by the terminaldevice, a reference signal sequence based on parameters of a firstbandwidth and parameters of a second bandwidth includes: determining, bythe terminal device, the reference signal sequence based on a subcarrierspacing and the parameters of the first bandwidth, the parameters of thesecond bandwidth.

Specifically, at different moments, numerologies or subcarrier spacingsmay be different, and frequency domain lengths of an RB that correspondto different numerologies or subcarrier spacings are also different.Therefore, when numerologies or subcarrier spacings used at differentmoments are different, the offset value needs to be determined based ona numerology or a subcarrier spacing at a current moment, therebydetermining a reference signal sequence, that is, the offset value needsto be determined based on the numerology or the subcarrier spacing atthe current moment.

It should be further understood that, the offset value is related to anoffset value of the frequency domain of the first bandwidth relative tothat of the second bandwidth. If an offset value of the frequency domainstart position of the first bandwidth relative to the frequency domainstart position of the second bandwidth is N RBs, the offset value isequal to N. An RB quantity of the offset value is calculated based on asubcarrier spacing on the carrier and a quantity of subcarriers in anRB. In this way, it may be ensured that regardless of whether theterminal device accesses the first bandwidth or the second bandwidth, ifused OCCs and sequence initialization values are the same, correspondingused reference signal sequences are the same as long as a frequencydomain position is fixed.

It should be further understood that, a method for determining areference signal sequence on a CC is provided above. The terminal devicemay further access a plurality of CCs by using CA, and reference signalson other CCs may also be determined based on a similar method. Forexample, the terminal device accesses CC1, CC2, CC3, and the like, eachof CC1, CC2, and CC3 may be considered as the first bandwidth. When theterminal device accesses a plurality of CCs, a CC may be considered as aCC of a primary cell, and other CCs are CCs of a secondary cell. When asynchronization signal detected by the terminal device is asynchronization signal of the CC of the primary cell, if CC1 is the CCof the primary cell, after determining a center frequency and abandwidth of CC1 and accessing CC1, the terminal device may receiveindication information sent by the network device, determine frequencydomain offset values of CC2 and CC3 relative to CC1 based on theindication information, and then determine, based on related parametersof CC1 and the second bandwidth, values of offset2 and offset3 ofreference signal sequences on CC2 and CC3 relative to the secondbandwidth.

It should be further understood that, in a case of using CA, whetherthere is a guard bandwidth between CCs further needs to be considered.In LTE, or NR, some blank subcarriers are used between different CCs toserve as a guard bandwidth. FIG. 6 is a schematic diagram of determiningan offset value according to another embodiment of this application. Asshown in FIG. 6, in NR or LTE, if a guard bandwidth of N subcarriersexists between CCs, when an offset value of a reference signal sequenceof each CC is calculated, a frequency domain length of the guardbandwidth (GB) between the CCs needs to be taken into account.

It should be further understood that, only a method for mapping areference signal sequence similar to that in LTE is used as an examplein this embodiment of this application, but the embodiments of thisapplication may further include another method for mapping a referencesignal sequence. Moreover, the essence of the method of the embodimentsof this application is likewise applicable to another reference sequencehaving a similar sequence generating and mapping rule, for example,another uplink or downlink reference signal sequence, as long as mappingof the reference signal is related to a number of an RB of the foregoingterminal device. This embodiment of this application is not limitedherein.

It should be further understood that, the parameters of the secondbandwidth and the parameters of the first bandwidth may further includeother parameters, and this embodiment of this application is not limitedherein.

Optionally, in an embodiment, the method 100 further includes;receiving, by the terminal device, second indication information sent bythe network device; and determining, by the terminal device, at leastone of the parameters of the second bandwidth based on the secondindication information.

Specifically, in a process of initially accessing the first bandwidth,the terminal device detects a synchronization signal of the firstbandwidth. After the synchronization signal is determined, because thesynchronization signal is on the center frequency of the firstbandwidth, the synchronization signal is detected, and the centerfrequency of the first bandwidth can be determined. Then, the parametersof the first bandwidth are obtained based on broadcast information ofthe network device.

For the parameters of the second bandwidth, the terminal device receivesthe second indication information sent by the network device, and thesecond indication information is used by the terminal device todetermine at least one of the parameters of the second bandwidth thatmay be, for example, at least one of the bandwidth value of the secondbandwidth, the frequency domain start position of the second bandwidth,and the center frequency of the second bandwidth of the parameters ofthe second bandwidth.

After obtaining the parameters of the first bandwidth and the parametersof the second bandwidth, the terminal device may determine an offsetvalue of the frequency domain of the first bandwidth relative to thefrequency domain of the second bandwidth based on the information,determine the mapping formula of the reference signal sequence on thefirst bandwidth by using Formula (5) or Formula (6), and finallydetermine the reference signal sequence on the first bandwidth.

It should be understood that, the network device may predefine M (M≥1)second bandwidths. For example, the second bandwidth may include one ormore of bandwidths such as a maximum bandwidth, a cell bandwidth, awideband CC, a bandwidth after aggregation of a plurality of CCs, and awideband BP. The network device may notify, by using the secondindication information of log₂ M bits, the terminal device of theparameters of the second bandwidth. This embodiment of this applicationis not limited herein.

It should be further understood that, the network device may notpredefine the parameters of the second bandwidth. In this case, thenetwork device may send all possible parameter values of the secondbandwidth to the terminal device by using the indication information,and this embodiment of this application is not limited herein.

It should be further understood that, when the terminal devicedetermines the frequency domain start position of the second bandwidthby using the second indication information, the network device mayconfigure a frequency domain start position of a second bandwidth forthe terminal device, this is equivalent to that the network deviceconfigures a virtual bandwidth, and the virtual bandwidth and the actualsecond bandwidth may be different or the same. In this case, a length ofthe reference signal sequence is related to the frequency domain startposition of the virtual bandwidth, and a generation length of areference signal sequence on a wideband, a wideband CC, or a BP on whicha terminal device accessing the CC to perform MU-MIMO is located is alsorelated to the frequency domain start position of the virtual bandwidth;otherwise, on a same frequency domain, values of reference signalsequences of terminal devices accessing a CC and accessing a widebandmay still be different, and cannot he configured to be orthogonal. Thenetwork device may also predefine one or more virtual bandwidths, andconfigure one of the virtual bandwidths for the terminal device, theterminal device determines a frequency domain start position of a secondbandwidth by using a virtual bandwidth and a center frequency of thesecond bandwidth, and then calculates a frequency domain offset of afrequency domain start position of a CC relative to a start position ofthe virtual bandwidth, and a generation length of a reference signalsequence on the CC may also be generated based on a length of thevirtual bandwidth.

Optionally, a resource used to carry the second indication informationincludes: any one of a broadcast message, Radio Resource Control (RRC)signaling, a synchronization signal, a synchronization signal block, aMedia Access Control control element (MAC CE), and downlink controlinformation (DCI).

It should be understood that, the broadcast message may be a masterinformation block (MIB) or a system information block (SIB), and mayfurther be another type of broadcast message, and this embodiment ofthis application is not limited herein.

Specifically, the terminal device receives the second indicationinformation sent by the network device, and the second indicationinformation may be carried in any one of broadcast signaling, higherlayer signaling, and physical signaling, and is used to notify theterminal device of the parameters of the second bandwidth. For example,the terminal device may receive the second indication information onsignaling such as UE-specific signaling, UE group specific signaling,cell specific signaling, or group common signaling.

It should be understood that, the resource used to carry the secondindication information may be further another resource or anothersignaling, and this embodiment of this application is not limitedherein.

It should be further understood that, the terminal device may furtherdetermine other parameters of the second bandwidth by using the secondindication information, and this embodiment of this application is notlimited herein.

Optionally, in an embodiment, the method 100 further includes:receiving, by the terminal device, third indication information sent bythe network device; and determining, by the terminal device, at leastone of the parameters of the first bandwidth based on the thirdindication information.

Specifically, in a process of initially accessing the second bandwidth,the terminal device detects a synchronization signal of the secondbandwidth. After the synchronization signal is determined, because thesynchronization signal is on the center frequency of the secondbandwidth, the synchronization signal is detected, and the centerfrequency of the second bandwidth can be determined. Then, theparameters of the second bandwidth are learned based on broadcastinformation of the network device.

For the parameters of the first bandwidth, the terminal device receivesthe third indication information sent by the network device, and thethird indication information is used by the terminal device to determineat least one of the parameters of the first bandwidth that may be, forexample, the bandwidth value of the first bandwidth, the frequencydomain start position of the first bandwidth, and the center frequencyof the first bandwidth.

After obtaining the parameters of the first bandwidth and the parametersof the second bandwidth, the terminal device may determine an offsetvalue of the frequency domain of the first bandwidth relative to thefrequency domain of the second bandwidth based on the information,determine the mapping formula of the reference signal sequence on thefirst bandwidth by using Formula (5), and finally determine thereference signal sequence on the first bandwidth.

It should be understood that, the terminal device may further obtain theparameters of the first bandwidth and the parameters of the secondbandwidth by using another method, and this embodiment of thisapplication is not limited herein.

It should be further understood that, the network device may predefine M(M≥1) first bandwidths. For example, the first bandwidth may include oneor more of bandwidths such as a CC, a BP, and a wideband bandwidth. Thenetwork device may notify, by using the third indication information oflog₂M bits, the terminal device of the parameters of the firstbandwidth. This embodiment of this application is not limited herein.

It should be further understood that, the network device may notpredefine the parameters of the first bandwidth. In this case, thenetwork device may send all possible parameter values to the terminaldevice by using the third indication information, and this embodiment ofthis application is not limited herein.

Optionally, a resource used to carry the third indication informationincludes: any one of a broadcast message, RRC signaling, asynchronization signal, a synchronization signal block, a MAC CE, andDCI.

Specifically, the terminal device receives the third indicationinformation sent by the network device, and the third indicationinformation may be carried in any one of broadcast signaling, higherlayer signaling, and physical signaling, and is used to notify theterminal device of information about the parameters of the secondbandwidth. For example, the terminal device may receive the thirdindication information n signaling such as UE-specific signaling, UEgroup specific signaling, cell specific signaling, or group commonsignaling.

It should be understood that, the resource used to carry the thirdindication information may be further another resource or anothersignaling, and this embodiment of this application is not limitedherein.

It should be further understood that, the terminal device may furtherdetermine other parameters of the first bandwidth by using the thirdindication information, and this embodiment of this application is notlimited herein.

Optionally, the terminal device may further determine an offset value ofthe frequency domain of the first bandwidth relative to that of thesecond bandwidth by using the second indication information. Forexample, a frequency domain resource element may be used as a basicunit, and a method for notifying the offset value may be notifying thatthe offset value is N times the frequency domain resource element. Thefrequency domain resource element may be an RB, a PRB, a resource blockgroup (RBG), a preceding resource block group (PRG), or the like. Thefrequency domain resource element may have a plurality of candidatevalues and is designated by the network device, or selection of thefrequency domain resource element is related to an identifier of a CC ora wideband CC. The terminal device determines an offset value based onindication information of the network device and a size of a frequencydomain of an RB in a system in which the terminal device is currentlylocated. This embodiment of this application is not limited herein.

It should be understood that, the terminal device accessing the firstbandwidth and the terminal device accessing the second bandwidth mayfurther adjust an offset value in a reference signal mapping formula byusing a third bandwidth as a reference. For example, the first bandwidthis a CC, the second bandwidth is a wideband CC, and the third bandwidthmay be a cell bandwidth or a maximum system bandwidth. Both a bandwidthof the CC and a bandwidth of the wideband CC are a part of the cellbandwidth or the maximum system bandwidth. In this case, both theterminal device accessing the first bandwidth and the terminal deviceaccessing the second bandwidth may calculate a frequency domain offsetvalue of the first bandwidth relative to the third bandwidth and afrequency domain offset value of the second bandwidth relative to thethird bandwidth by using a frequency domain start position of the thirdbandwidth as a reference, and then may obtain an offset value to which areference signal on the first bandwidth is mapped and an offset value towhich a reference signal on the second bandwidth is mapped. In themethod, the terminal device on the first bandwidth and the terminaldevice on the second bandwidth may be likewise configured to performMU-MIMO as long as that the third bandwidth is greater than the firstbandwidth and the second bandwidth is satisfied. This embodiment of thisapplication is not limited herein.

It should be further understood that, in this embodiment of thisapplication, the foregoing method for determining a reference signalsequence not only may satisfy that different terminal devices on a CC, awideband CC, a BP, and a cell bandwidth perform MU-MIMO, but also maysatisfy that different terminal devices on a maximum system bandwidthand the like perform MU-MIMO. In a new wireless communications system,each reference signal may also be determined based on the methodprovided in this application. This embodiment of this application is notlimited herein.

It should be further understood that, in this embodiment of thisapplication, the offset value may further be 0, and if MU-MIMO betweenusers among a CC, a wideband CC, a BP, a cell bandwidth, and a maximumsystem bandwidth does not need to be supported, each offset value offsetin the foregoing formula for mapping a reference signal on a bandwidthmay be 0. Therefore, the network device may further indicate, based onwhether a terminal device on the first bandwidth (a CC, a BP, a widebandCC, or the like) and a terminal device on another bandwidth performMU-MIMO, whether the terminal devices use the technical solution of thisapplication, that is, indicate an offset value offset to which areference signal is mapped is 0 or is related to parameters such as thefirst bandwidth and the second bandwidth. The terminal device maydetermine, based on indication information sent by the network device,whether the offset value to which the reference signal is mapped is 0 orneeds to be calculated based on the parameters such as the firstbandwidth and the second bandwidth. The network device indicate, byusing the indication information such as indication informationindicating that the network device uses X (X≥1) bits, that at a momentor in a period of time, an offset in the mapping formula is set to a, orthe network device may determine, by using the indication information,that the terminal device needs to calculate the offset value in themapping formula. When having not received indication information of anetwork side device, the terminal device may use the solution in theprior art (that is, an offset value is 0) or the solution of thisapplication (an offset value is calculated based on the parameters suchas the first bandwidth and the second bandwidth) by default. Thisembodiment of this application is not limited herein.

It should be further understood that, sequence numbers of the foregoingprocesses do not mean execution orders in this embodiment of thisapplication. The execution orders of the processes should be determinedbased on functions and internal logic of the processes, and should notbe construed as any limitation on the implementation processes of theembodiments of this application.

Based on the method for determining a reference signal sequence providedin this embodiment of this application, after determining the parametersof the second bandwidth based on the indication information sent by thenetwork device, the terminal device determines the reference signalsequence based on the parameters of the second bandwidth and theparameters of the first bandwidth, so that the reference signal sequenceon the first bandwidth and the reference signal sequence on the secondbandwidth may be configured to be the same, orthogonal, orquasi-orthogonal. When different terminal devices respectively accessthe first bandwidth and the second bandwidth to perform MU-MIMO, thereference signal sequence on the first bandwidth and the referencesignal sequence on the second bandwidth may be configured to beorthogonal or quasi-orthogonal, to support MU-MIMO between the terminaldevices operating on the first bandwidth and the second bandwidth. Userexperience is improved.

This application further provides a method 200 for determining areference signal sequence, and the method 200 may be performed by anetwork device. FIG. 7 is a schematic flowchart of the method 200 fordetermining a reference signal sequence according to an embodiment ofthis application. As shown in FIG. 7, the method 200 includes thefollowing steps.

S210. A network device sends first indication information to a terminaldevice, where the first indication information indicates a targetresource.

S220. The network device sends second indication information to theterminal device, where the second indication information is used toindicate at least one of parameters of a second bandwidth.

Specifically, in S210, when the terminal device needs to send data on atime-frequency resource, the network device sends the first indicationinformation to the terminal device, the first indication information isused to indicate a particular time-frequency resource to the terminaldevice, that is, the target resource, the target resource is a resourceallocated by the network device to the terminal device, and the terminaldevice may send or receive data on the target resource. The terminaldevice may send a reference signal sequence on the target resource, andthe reference signal sequence is used by the network device to correctlyperform channel estimation, coherent detection, and demodulation, sothat the network device correctly demodulates data of the terminaldevice.

In S220, because NR needs to support MU-MIMO between a terminal deviceoperating on a wideband (or a wideband CC) or a BP and a terminal deviceoperating on a CC or using aggregation of a plurality of CCs, thenetwork device needs to demodulate data sent by different terminaldevices. In this case, reference signal sequences sent by the differentterminal devices need to be configured to be orthogonal orquasi-orthogonal.

When MU-MIMO between the terminal device operating on the firstbandwidth and the terminal device operating on the second bandwidth issupported, and when the terminal device accesses the first bandwidth,the reference signal sequence needs to be determined based on theparameters of the first bandwidth and the parameters of the secondbandwidth, and the reference signal sequence is sent on the targetresource. Therefore, the reference signal sequence on the firstbandwidth and the reference signal sequence on the second bandwidth maybe configured to be the same, orthogonal, or quasi-orthogonal, a.MU-MIMO between the terminal devices operating on the first bandwidthand the second bandwidth may be supported. Therefore, the network devicesends the second indication information to the terminal device, and thesecond indication information is used by the terminal device todetermine the parameters of the second bandwidth.

When the terminal device accesses the first bandwidth, the terminaldevice detects a synchronization signal of the first bandwidth. Afterthe synchronization signal is determined, because the synchronizationsignal is on the center frequency of the first bandwidth, thesynchronization signal is detected, and the center frequency of thefirst bandwidth can be determined. Then, the network device notifiesother parameters of the first bandwidth by using broadcast information.For the parameters of the second bandwidth, the network device sends thesecond indication information to the terminal device, and the secondindication information is used by the terminal device to determine atleast one of the parameters of the second bandwidth that may be, forexample, at least one of a bandwidth value of the second bandwidth, afrequency domain start position of the second bandwidth, and a centerfrequency of the second bandwidth.

Based on the method for determining a reference signal sequence providedin this embodiment of this application, the network device sends, to theterminal device, the indication information used to indicate theparameters of the second bandwidth, and MU-MIMO between the terminaldevice operating on the first bandwidth and the terminal deviceoperating on the second bandwidth may be supported, that is, a referencesignal sequence is determined based on parameters of the first bandwidthand the parameters of the second bandwidth. Finally, a reference signalsequence on the first bandwidth and a reference signal sequence on thesecond bandwidth are configured to be the same, orthogonal, orquasi-orthogonal, and MU-MIMO between the terminal devices operating onthe first bandwidth and the second bandwidth may be supported. Thenetwork device may correctly parse data in different terminal devices.

It should be understood that, the target resource is a resourceallocated by the network device to the terminal device, and the terminaldevice may send or receive data on the target resource. A frequencydomain of the target resource and a frequency domain of the firstbandwidth may be the same or partially overlap. The frequency domain ofthe target resource may further be a part of a frequency domain of thesecond bandwidth, or a part of the frequency domain of the firstbandwidth. This embodiment of this application is not limited herein.

It should be further understood that, the first bandwidth may includeeither of an operating bandwidth of the terminal device and a cellbandwidth serving the terminal &vice. For example, the first bandwidthmay be a CC or a BP. The second bandwidth may include any one of amaximum system bandwidth, a cell bandwidth, and a wideband carrierbandwidth. The frequency domain of the first bandwidth may be a part ofthe frequency domain of the second bandwidth, and the bandwidth value ofthe first bandwidth may be less than the bandwidth value of the secondbandwidth. This embodiment of this application is not limited herein.

Optionally, a resource used to early the second indication informationincludes: any one of a broadcast message, RRC signaling, asynchronization signal, a synchronization signal block, a MAC CE, andDCI.

Specifically, when the network device sends the second indicationinformation to the terminal device, the second indication informationmay be carried in any one of broadcast signaling, higher layersignaling, and physical signaling, and is used to notify the terminaldevice of information about the parameters of the second bandwidth. Forexample, the network device may carry the second indication informationby using signaling such as UE-specific signaling, UE group specificsignaling, cell specific signaling, or group common signaling.

It should be understood that, the resource used to carry the secondindication information may be further another resource or anothersignaling, and this embodiment of this application is not limitedherein.

It should be further understood that, the network device may furthernotify other parameters of the second bandwidth by using the secondindication information, and this embodiment of this application is notlimited herein.

It should be further understood that, the network device may predefine M(M≥1) second bandwidths. For example, the second bandwidth may includeone or more of bandwidths such as a maximum bandwidth, a cell bandwidth,a wideband bandwidth, a bandwidth after aggregation of a plurality ofCCs, and a wideband BP. The network device may notify, by using thesecond indication information of log₂ M bits, the terminal device of atleast one of the parameters of the second bandwidth. This embodiment ofthis application is not limited herein.

It should be further understood that, the network device may notpredefine the parameters of the second bandwidth. In this case, thenetwork device may send all possible parameter values to the terminaldevice by using the indication information, and this embodiment of thisapplication is not limited herein.

Optionally, in an embodiment, the method 200 further includes: sending,by the network device, third indication information to the terminaldevice, where the third indication information is used to indicate atleast one of parameters of a first bandwidth.

Specifically, when the terminal device accesses the second bandwidth,the terminal device detects a synchronization signal of the secondbandwidth. After the synchronization signal is determined, because thesynchronization signal is on the center frequency of the secondbandwidth, the synchronization signal is detected, and the centerfrequency of the second bandwidth can be determined. Then, the networkdevice notifies other parameters of the second bandwidth by usingbroadcast information. For the parameters of the first bandwidth, thenetwork device sends the third indication information to the terminaldevice, and the third indication information is used by the terminaldevice to determine at least one of the parameters of the firstbandwidth that may be, for example, the bandwidth value of the firstbandwidth, the frequency domain start position of the first bandwidth,and the center frequency of the first bandwidth.

Optionally, a resource used to carry the third indication informationincludes: any one of a broadcast message, RRC signaling, asynchronization signal, a synchronization signal block, a MAC CE, andDCI.

Specifically, when the network device sends the third indicationinformation to the terminal device, the third indication information maybe carried in any one of broadcast signaling, higher layer signaling,and physical signaling, and is used to notify the terminal device ofinformation about the parameters of the first bandwidth. For example,the network device may carry the third indication information by usingsignaling such as UE-specific signaling, UE group specific signaling,cell specific signaling, or group common signaling.

It should be understood that, the resource used to carry the thirdindication information may be further another resource or anothersignaling, and this embodiment of this application is not limitedherein.

It should be further understood that, the network device may furthernotify information about other parameters of the first bandwidth byusing the third indication information, and this embodiment of thisapplication is not limited herein.

It should be further understood that, the network device may predefine M(M.≥1) first bandwidths, and the first bandwidth may include one or moreof bandwidths such as a CC, a BP, and a wideband bandwidth. The networkdevice may notify, by using the third indication information of log₂ Mbits, the terminal device of the parameters of the first bandwidth. Thisembodiment of this application is not limited herein.

It should be understood that, a frequency domain of the target resourceand a frequency domain of the first bandwidth may be the same orpartially overlap. The frequency domain of the target resource mayfurther be a part of a frequency domain of the second bandwidth, or apart of the frequency domain of the first bandwidth. This embodiment ofthis application is not limited herein.

Optionally, in an embodiment, the first bandwidth may include any one ofan operating bandwidth of the terminal device, a cell bandwidth servingthe terminal device, and a carrier bandwidth. For example, the firstbandwidth may be a CC, a plurality of CCs after carrier aggregation, aBP, a cell bandwidth, a maximum system bandwidth, or the like. Thesecond bandwidth may include any one of a maximum system bandwidth, acell bandwidth, and a wideband carrier bandwidth. The frequency domainof the first bandwidth may be a part of the frequency domain of thesecond bandwidth, or the frequency domain of the first bandwidth and apart of the frequency domain of the second bandwidth overlap, and abandwidth value of the first bandwidth may be less than or equal to abandwidth value of the second bandwidth. This embodiment of thisapplication is not limited herein.

Optionally, in an embodiment, the parameters of the second bandwidthinclude at least one of the following parameters: a center frequency ofthe second bandwidth, a bandwidth value of the second bandwidth, and afrequency domain start position of the second bandwidth.

Optionally, in an embodiment, the parameters of the first bandwidthinclude at least one of the following parameters: a center frequency ofthe first bandwidth, a bandwidth value of the first bandwidth, and afrequency domain start position of the first bandwidth.

Specifically, a method for generating a reference signal on the firstbandwidth may be the same as or different from a method for generating areference signal on the second bandwidth, or a length of the referencesignal sequence generated on the first bandwidth and the secondbandwidth needs to be generated based on a maximum value of the twobandwidths or another larger bandwidth value. That is, a generatedlength of a reference signal on the first bandwidth is generated basedon the second bandwidth, or both a reference signal on the firstbandwidth and the reference signal sequence on the second bandwidth aregenerated based on the maximum bandwidth. Reference sequences of anoverlapping part of the first bandwidth and the second bandwidth infrequency domain may be configured to be the same, orthogonal, orquasi-orthogonal. Because the frequency domain start position of thefirst bandwidth and the frequency domain start position of the secondbandwidth may be different, it may be considered that the frequencydomain start position of the first bandwidth has an offset valuerelative to the frequency domain start position of the second bandwidth,and corresponding to a mapping formula of a reference signal sequence, amapping formula of the reference signal sequence on the first bandwidthhas an offset value relative to a mapping formula of the referencesignal sequence on the second bandwidth. The parameters of the firstbandwidth include at least one of the following parameters: a centerfrequency of the first bandwidth, a bandwidth value of the firstbandwidth, and a frequency domain start position of the first bandwidth.The offset value is related to the parameters of the first bandwidth andthe parameters of the second bandwidth. The parameters of the secondbandwidth include at least one of the center frequency of the secondbandwidth, the bandwidth value of the second bandwidth, and thefrequency domain start position of the second bandwidth.

The offset value of the frequency domain start position of the firstbandwidth relative to that of the second bandwidth may be determinedbased on the parameters of the first bandwidth and the parameters of thesecond bandwidth, to obtain the mapping formula of the reference signalsequence on the first bandwidth, the reference signal sequence on thefirst bandwidth may be made the same as the reference signal sequence onthe second bandwidth by using respective mapping formulas, and thereforethe reference signal sequence on the first bandwidth and the referencesignal sequence on the second bandwidth may be configured to beorthogonal or quasi-orthogonal.

Optionally, the network device may notify the terminal device of theoffset value of the frequency domain of the first bandwidth relative tothat of the second bandwidth by using the second indication information.For example, a frequency domain resource element may be used as a basicunit, and a method for notifying the offset value may be notifying thatthe offset value is N times the frequency domain resource element. Thefrequency domain resource element may be an RB, a PRB, an RBG, a PRG, orthe like. The frequency domain resource element may have a plurality ofcandidate values that are designated by the network device, or selectionof the frequency domain resource element is related to an identifier ofa CC or a wideband CC. The terminal device determines an offset valuebased on indication information of the network device and a size of afrequency domain of an RB in a system in which the terminal device iscurrently located. This embodiment of this application is not limitedherein.

It should be further understood that, the network device may furthersend, to the terminal device, indication information used to informabout whether a plurality of terminal devices need to perform MU-MIMO.For example, the network device may indicate, by using indicationinformation of X (X≥1) bits, that at a moment or in a period of time, anoffset in the mapping formula is set to 0. Alternatively, the networkdevice may determine, by using the indication information, to inform theterminal device that the offset value in the mapping formula needs to becalculated. This embodiment of this application is not limited herein.

It should be further understood that, sequence numbers of the foregoingprocesses do not mean execution orders in this embodiment of thisapplication. The execution orders of the processes should be determinedbased on functions and internal logic of the processes, and should notbe construed as any limitation on the implementation processes of theembodiments of this application.

Based on the method for determining a reference signal sequence providedin this embodiment of this application, the network device sends, to theterminal device, the second indication information used to indicate theparameters of the second bandwidth and the third indication informationused to indicate the parameters of the first bandwidth, and MU-MIMObetween the terminal device operating on the first bandwidth and theterminal device operating on the second bandwidth may be supported, thatis, a reference signal sequence is determined based on parameters of thefirst bandwidth and the parameters of the second bandwidth. Finally, areference signal sequence on the first bandwidth and a reference signalsequence on the second bandwidth are configured to be the same,orthogonal, or quasi-orthogonal, to support MU-MIMO between the terminaldevices operating on the first bandwidth and the second bandwidth. Thenetwork device may correctly parse data in different terminal devices.

The method for determining a reference signal sequence of theembodiments of this application is described in detail above withreference to FIG. 1 to FIG. 7, and a terminal device and a networkdevice of this embodiment of this application is described in detailbelow with reference to FIG. 8 to FIG. 11.

FIG. 8 is a schematic block diagram of a terminal device according to anembodiment of this application. It should be understood that, theterminal device embodiment and the method embodiment correspond to eachother. For a similar description, refer to the method embodiment. Theterminal device 300 shown in FIG. 8 may be configured to perform stepsperformed by the terminal device corresponding to FIG. 3. The terminaldevice 300 includes: a processor 310, a memory 320, and a transceiver330. The processor 310, the memory 320, and the transceiver 330 areconnected by using communication, the memory 320 stores an instruction,the processor 310 is configured to execute the instruction stored in thememory 320, and the transceiver 330 is configured to perform specificsignal receiving/transmission under driving of the processor 310.

The transceiver 330 is configured to receive first indicationinformation sent by a network device.

The processor 310 is configured to determine a target resource based onthe first indication information.

The processor 310 is further configured to determine a reference signalsequence based on parameters of a first bandwidth and parameters of asecond bandwidth.

The transceiver 330 is further configured to send or receive thereference signal sequence on the target resource.

The terminal device provided in this embodiment of this application candetermine the reference signal sequence based on the parameters of thefirst bandwidth and the parameters of the second bandwidth, so that areference signal sequence on the first bandwidth and a reference signalsequence on the second bandwidth are the same. When different terminaldevices respectively access the first bandwidth and the second bandwidthto perform MU-MIMO, the reference signal sequence on the first bandwidthand the reference signal sequence on the second bandwidth may beconfigured to be the same, orthogonal, or quasi-orthogonal, to supportMU-MIMO between the terminal devices operating on the first bandwidthand the second bandwidth, improving user experience.

Components in the terminal device 300 are connected by usingcommunication, that is, the processor 310, the memory 320, and thetransceiver 330 communicate with each other and transfer a controland/or data signal between each other by using an internal connectionpath. The foregoing method embodiment of this application may be appliedto the processor, or the processor implements steps of the foregoingmethod embodiment. The processor may be an integrated circuit chip andhas a signal processing capability. In an implementation process, thesteps in the foregoing method embodiments may be completed by using anintegrated logic circuit of hardware in the processor or an instructionin a form of software. The processor may be a central processing unit(CPU), a network processor (NP), a combination of a CPU and an NP, adigital signal processor (DSP), an application-specific integratedcircuit (ASIC), a field programmable gate array (FPGA), anotherprogrammable logic device, a discrete gate, a transistor logic device,or a discrete hardware component. The processor may implement or performmethods, steps, and logical block diagrams disclosed in thisapplication. The general purpose processor may be a microprocessor, orthe processor may be any conventional processor or the like. Steps ofthe methods disclosed in this application may be directly performed andcompleted by a hardware decoding processor, or may be performed andcompleted by using a combination of hardware and software modules in thedecoding processor. The software module maybe located in a maturestorage medium in the art, such as a random access memory, a flashmemory, a read-only memory, a programmable read-only memory, anelectrically erasable programmable read-only memory, or a register. Thestorage medium is located in the memory, and the processor readsinformation in the memory, and completes the steps of the foregoingmethods in combination with hardware of the processor.

Optionally, in another embodiment of this application, the parameters ofthe second bandwidth include at least one of the following parameters: acenter frequency of the second bandwidth, a bandwidth value of thesecond bandwidth, and a frequency domain start position of the secondbandwidth.

Optionally, in another embodiment of this application, the parameters ofthe first bandwidth include at least one of the following parameters: acenter frequency of the first bandwidth, a bandwidth value of the firstbandwidth, and a frequency domain start position of the first bandwidth.

Optionally, in another embodiment of this application, the transceiver330 is further configured to receive second indication information sentby the network device; and the processor 310 is further configured todetermine at least one of the parameters of the second bandwidth basedon the second indication information.

Optionally, in another embodiment of this application, the transceiver330 is further configured to receive third indication information sentby the network device; and the processor 310 is further configured todetermine at least one of the parameters of the first bandwidth based onthe third indication information.

Optionally, in another embodiment of this application, the processor 310is specifically configured to determine the reference signal sequencebased on a subcarrier spacing and the parameters of the first bandwidth,the parameters of the second bandwidth.

Optionally, in another embodiment of this application, a frequencydomain of the target resource determined by the processor 330 arid afrequency domain of the first bandwidth are the same or partiallyoverlap.

Optionally, in another embodiment of this application, the bandwidthvalue of the first bandwidth is less than the bandwidth value of thesecond bandwidth.

Optionally, in another embodiment of this application, the firstbandwidth is any one of an operating bandwidth of the terminal device,aserving cell bandwidth, and a carrier bandwidth; and the secondbandwidth is any one of a maximum system bandwidth, a cell bandwidth,and a wideband carrier bandwidth.

It should be noted that, in this embodiment of this application, theprocessor 310 may be implemented by a processing module, the memory 320may be implemented by a storage module, and the transceiver 330 may beimplemented by a transceiver module. As shown in FIG. 9, a terminaldevice 400 may include a processing module 410, a storage module 420,and a transceiver module 430.

The terminal device 300 shown in FIG. 8 or the terminal device 400 shownin FIG. 9 can implement steps performed by the terminal device in FIG.3. To avoid repetition, details are not described herein again.

FIG. 10 is a schematic block diagram of a network device 500 accordingto an embodiment of this application. It should be understood that, thenetwork device embodiment and the method embodiment correspond to eachother. For a similar description, refer to the method embodiment. Asshown in FIG. 10, the network device 500 includes: a processor 510, amemory 520, and a transceiver 530. The processor 510, the memory 520,and the transceiver 530 are connected by using communication, the memory520 stores an instruction, the processor 510 is configured to executethe instruction stored in the memory 520, and the transceiver 530 isconfigured to perform specific signal receiving/transmission underdriving of the processor 510.

The transceiver 530 is configured to send first indication informationto a terminal device, where the first indication information is used toindicate a target resource.

The transceiver 530 is further configured to send second indicationinformation to the terminal device, where the second indicationinformation is used to indicate at least one of parameters of a secondbandwidth.

Based on the network device provided in this embodiment of thisapplication, the network device sends, to the terminal device, theindication information used to indicate the parameters of the secondbandwidth, and MU-MIMO between UE operating on a first bandwidth and UEoperating on the second bandwidth may be supported, that is, a referencesignal sequence is determined based on parameters of the first bandwidthand the parameters of the second bandwidth. Finally, a reference signalsequence on the first bandwidth and a reference signal sequence on thesecond bandwidth are configured to be the same, orthogonal, orquasi-orthogonal, to support MU-MIMO between the terminal devicesoperating on the first bandwidth and the second bandwidth. The networkdevice may correctly parse data in different terminal devices.

Components in the network device 500 are connected by singcommunication, that is, the processor 510, the memory 520, and thetransceiver 530 communicate with each other and transfer a controland/or data signal between each other by using an internal connectionpath. It should be noted that, the foregoing method embodiment of thisapplication may be applied to the processor, or the processor implementssteps of the foregoing method embodiment. The processor may be anintegrated circuit chip and has a signal processing capability. In animplementation process, the steps in the foregoing method embodimentsmay be completed by using an integrated logic circuit of hardware in theprocessor or an instruction in a form of software. The processor may bea central processing unit CPU, an NP, combination of a CPU and an NP, aDSP, an ASIC, an FPGA, another programmable logic device, a discretegate, a transistor logic device, or a discrete hardware component. Theprocessor may implement or perform methods, steps, and logical blockdiagrams disclosed in this application. The general purpose processormay be a microprocessor, or the processor may be any conventionalprocessor or the like. Steps of the methods disclosed in thisapplication may be directly performed and completed by a hardwaredecoding processor, or may be performed and completed by using acombination of hardware and software modules in the decoding processor.The software module may be located in a mature storage medium in theart, such as a random access memory, a flash memory, a read-only memory,a programmable read-only memory, an electrically erasable programmableread-only memory, or a register. The storage medium is located in thememory, and the processor reads information in the memory, and completesthe steps of the foregoing methods in combination with hardware of theprocessor.

Optionally, in another embodiment of this application, the transceiver530 is further configured to send third indication information to theterminal device, where the third indication information is used toindicate at least one of the parameters of the first bandwidth.

Optionally, in another embodiment of this application, the parameters ofthe second bandwidth and the parameters of the first bandwidth are usedby the terminal device to determine a reference signal sequence, and thereference signal sequence is sent on the target resource.

Optionally, in another embodiment of this application, the parameters ofthe second bandwidth include at least one of the following parameters: acenter frequency of the second bandwidth, a bandwidth value of thesecond bandwidth, and a frequency domain start position of the secondbandwidth.

Optionally, in another embodiment of this application, the parameters ofthe first bandwidth include at least one of the following parameters: acenter frequency of the first bandwidth, a bandwidth value of the firstbandwidth, and a frequency domain start position of the first bandwidth.

Optionally, in another embodiment of this application, a frequencydomain of the target resource and a frequency domain of the firstbandwidth are the same or partially overlap. The bandwidth value of thefirst bandwidth is less than the bandwidth value of the secondbandwidth.

Optionally, in another embodiment of this application, the firstbandwidth is any one of an operating bandwidth of the terminal device, aserving cell bandwidth, and a carrier bandwidth; and the secondbandwidth is any one of a maximum system bandwidth, a cell bandwidth,and a wideband carrier bandwidth.

It should be noted that, in this embodiment of the present invention,the processor 510 may be implemented by a processing module, the memory520 may be implemented by a storage module, and the transceiver 530 maybe implemented by a transceiver module. As shown in FIG. 11, a networkdevice 600 may include a processing module 610, a storage module 620,and a transceiver module 630.

The network device 500 shown in FIG. 10 or the network device Goo shownin FIG. 11 can implement steps performed by the network device in FIG.7. To avoid repetition, details are not described herein again.

An embodiment of this application further provides a computer readablemedium. The computer readable medium is configured to store a computerprogram, and the computer program includes an instruction configured toperform the method for determining a reference signal sequence of theimplementations of this application in FIG. 3 and FIG. 7. The readablemedium may be a read-only memory (ROM) or a random access memory (RAM).This is not limited in this embodiment of this application.

An embodiment of this application further provides a communicationssystem. The communications system includes the terminal device providedin this embodiment of this application and the network device providedin this embodiment of this application, and the communications systemmay complete any method for determining a reference signal sequenceprovided in this embodiment of this application.

The term “and/or” and “at least one of A or B” in this specificationdescribes only an association relationship for describing associatedobjects and represents that three relationships may exist. For example,A and/or B may represent the following three cases: Only A exists, bothA and B exist, and only B exists. In addition, the character “/” in thisspecification generally indicates an “or” relationship between theassociated objects.

A person of ordinary skill in the art may be aware that, in combinationwith the examples described in the embodiments disclosed in thisspecification, units and algorithm steps may be implemented byelectronic hardware or a combination of computer software and electronichardware. Whether the functions are performed by hardware or softwaredepends on particular applications and design constraint conditions ofthe technical solutions. A person skilled in the art may use differentmethods to implement the described functions for each particularapplication, but it should not be considered that the implementationgoes beyond the scope of this application.

It may be clearly understood by a person skilled in the art that, forthe purpose of convenient and brief description, for a detailed workingprocess of the foregoing system, apparatus, and unit, refer to acorresponding process in the foregoing method embodiments, and detailsare flat described herein again.

In the several embodiments provided in this application, it should beunderstood that the disclosed system, apparatus, and method may beimplemented in other manners. For example, the described apparatusembodiment is merely an example. For example, the unit division ismerely logical function division and may be other division in actualimplementation. For example, a plurality of units or components may becombined or integrated into another system, or some features maybeignored or not performed. In addition, the displayed or discussed mutualcouplings or direct couplings or communication connections may beimplemented by using some interfaces. The indirect couplings orcommunication connections between the apparatuses or units may beimplemented in electronic, mechanical, or other forms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on a plurality ofnetwork units. Some or all of the units may be selected based on actualrequirements to achieve the objectives of the solutions of theembodiments.

In addition, functional units in the embodiments of this application maybe integrated into one processing unit, or each of the units may existalone physically, or two or more units are integrated into one unit.

When the functions are implemented in the form of a software functionalunit and sold or used as an independent product, the functions may bestored in a computer-readable storage medium. Based on such anunderstanding, the technical solutions of this application essentially,or the part contributing to the prior art, or some of the technicalsolutions may be implemented in a form of a software product. Thesoftware product is stored in a storage medium, and includes severalinstructions for instructing a computer device (which may be a personalcomputer, a server, or a network device) to perform all or some of thesteps of the methods described in this embodiment of this application.The foregoing storage medium includes: any medium that can store programcode, such as a USB flash drive, a removable hard disk, a ROM, a randomaccess memory (RAM), a magnetic disk, or an optical disc.

The foregoing descriptions are merely specific implementations of thisapplication, but are not intended to limit the protection scope of thisapplication. Any variation or replacement readily figured out by aperson skilled in the art within the technical scope disclosed in thisapplication shall fall within the protection scope of this application.Therefore, the protection scope of this application shall be subject tothe protection scope of the claims.

What is claimed is:
 1. A method for reference signal sequencetransmission, the method comprising: receiving first indicationinformation from a network device, the first indication informationindicating a bandwidth part; determining a reference signal sequencebased on an offset between a frequency domain start position of thebandwidth part and a frequency domain start position of a maximum systembandwidth; and sending or receiving the reference signal sequence viathe bandwidth part.
 2. The method according to claim 1, furthercomprising receiving second indication information from the networkdevice,the second indication information indicating the frequency domainstart position of the maximum system bandwidth.
 3. The method accordingto claim 1, further comprising receiving third indication informationfrom the network device, the third indication information indicating thefrequency domain start position of the bandwidth part.
 4. The methodaccording to claim 1, wherein determining the reference signal sequencecomprises determining the reference signal sequence based on asubcarrier spacing and the offset between the frequency domain startposition of the bandwidth part and the frequency domain start positionof the maximum system bandwidth.
 5. The method according to claim 1,wherein a bandwidth value of the bandwidth part is less than or equal toa bandwidth value of the maximum system bandwidth.
 6. A method forreference signal sequence transmission, comprising: sending firstindication information to a terminal device, the first indicationinformation indicating a bandwidth part; sending second indicationinformation to the terminal device, the second indication informationindicating a frequency domain start position of a maximum systembandwidth; and sending or receiving a reference signal sequence via thebandwidth part.
 7. The method according to claim 6, wherein the methodfurther comprises sending third indication information to the terminaldevice, the third indication information indicating a frequency domainstart position of the bandwidth part.
 8. The method according to claim7, wherein an offset between the frequency domain start position of thebandwidth part and the frequency domain start position of the maximumsystem bandwidth is used by the terminal device to determine a referencesignal sequence, and the reference signal sequence is sent via thebandwidth part.
 9. The method according to claim 6, wherein a bandwidthvalue of the bandwidth part is less than or equal to a bandwidth valueof the maximum system bandwidth.
 10. An apparatus, comprising: atransceiver; a non-transitory memory configured to store instructions;and a processor configured to execute the instructions stored in thenon-transitory memory and to control the transceiver to receive or senda signal; wherein the transceiver is configured to receive firstindication information from a network device, the first indicationinformation indicating a bandwidth part; wherein the processor isconfigured to determine a reference signal sequence based on an offsetbetween a frequency domain start position of the bandwidth part and afrequency domain start position of a maximum system bandwidth; andwherein the transceiver is further configured to send or receive thereference signal sequence via the bandwidth part.
 11. The apparatusaccording to claim 10, wherein the transceiver is further configured toreceive second indication information from the network device, thesecond indication information indicating the frequency domain startposition of the maximum system bandwidth.
 12. The apparatus according toclaim 10, wherein the transceiver is further configured to receive thirdindication information from the network device, the third indicationinformation indicating the frequency domain start position of thebandwidth part.
 13. The apparatus according to claim 10, wherein theprocessor is further configured to determine the reference signalsequence based on a subcarrier spacing and the offset between thefrequency domain start position of the bandwidth part and the frequencydomain start position of the maximum system bandwidth.
 14. The apparatusaccording to claim 10, wherein a bandwidth value of the bandwidth partis less than or equal to a bandwidth value of the maximum systembandwidth.
 15. An apparatus, comprising: a transceiver; a non-transitorymemory configured to store instructions; and a processor configured toexecute the instructions stored in the non-transitory memory and tocontrol the transceiver to receive or send a signal; wherein thetransceiver is configured to send first indication information to aterminal device, the first indication information indicating a bandwidthpart; wherein the transceiver is further configured to send secondindication information to the terminal device, the second indicationinformation indicating a frequency domain start position of a maximumsystem bandwidth; and wherein the transceiver is further configured tosend or receive a reference signal sequence via the bandwidth part. 16.The apparatus according to claim 15, wherein the transceiver is furtherconfigured to send third indication information to the terminal device,the third indication information indicating a frequency domain startposition of the bandwidth part.
 17. The apparatus according to claim 16,wherein an offset between the frequency domain start position of thebandwidth part and the frequency domain start position of the maximumsystem bandwidth is used by the terminal device to determine a referencesignal sequence, and the reference signal sequence is sent via thebandwidth part.
 18. The apparatus according to claim 15, wherein abandwidth value of the bandwidth part is less than or equal to abandwidth value of the maximum system bandwidth.